Certain electrical systems suffer from wear and other types of physical deterioration through use or age. In aircrafts, for example, vibration, moisture, temperature extremes, and improper maintenance may contribute to failure of components in electrical systems, including wiring failures. Loose connections, broken, frayed, and/or exposed wires, may cause arcing which may be the source of electrical ignition in aircraft wiring. Circuit breakers have historically been used to protect the wiring because it was recognized that electrical arcing in and around fuel pumps, boost pump motors and fuel quality indicators are dangerous.
Additional faults may occur as a result of carbon tracking or tracing, which can deteriorate wire insulation, so as to expose the conductors and result in intermittent short circuits between individual wires or to the air frame. Short circuits can cause damage to delicate avionic equipment or electrical equipment and cause system malfunctions while the aircraft is in flight.
In general, faults on power signals in power distribution systems pose a significant problem to systems or devices thereby powered. In certain systems electrical faults, such as arcing, can have catastrophic results. For instance, arcing from the electrical circuitry of an airline fuel pump may cause a fuel tank explosion leading to the loss of the aircraft. Similarly, arcing between wires proximate to the cockpit can cause sufficient cockpit smoke to also lead to an airliner crash. In less critical applications, such as commercial and industrial environments, electrical faults lead to significant damage, requiring inconvenient and often costly repairs.
Traditional solutions for electrical faults use circuit breakers, which can only detect ground faults and operate to shut down the electrical circuit after arcing has been occurring for some time. This protection circuitry is based upon current transformers and is large and bulky.
The problems with current fault detection systems are enhanced when dealing with electrical systems which are critical to the proper operation of the aircraft, and particularly when associated with aircraft fuel systems. For instance, in some circumstances fuel with an aircraft fuel tank will be depleted, or the craft may bank thereby displacing or “sloshing” the fuel within a tank, resulting in a temporary cessation of fuel being pumped. In circumstances where the fuel system includes a primer pump, the dry-running of the fuel can create a very dangerous condition, and may cause serious damage to the aircraft. Unfortunately, the current method of detecting and preventing a “run-dry” condition of the fuel primer pump involves a user detecting a decrease in fuel pressure, and a manual turning-off of the fuel pump. This approach is at best slow, and at worst, ineffective, at preventing hazardous “run-dry” condition.
It would be beneficial to provide an interrupter device that functions to detect potentially hazardous faults in power lines prior to the fault being passed downstream by “instantaneously” removing the power from a device when such faults are detected.